Device for stabilizing the trim of a floating object

ABSTRACT

The device for stabilizing the trim of a floating object comprises a mass of liquid contained in an enclosure inside of which is guided a piston associated with a jack, an installation comprising a variable delivery pump and a forcing pump for supplying a hydraulic motor whose output shaft is coupled up beyond an inertia flywheel to the driving shaft of a variable delivery pump supplying said jack, the pump being servocontrolled by the disturbing torque undergone by the floating object.

United States Patent [72] lnventor Gilbert Fonrnier Le lhvre, France [21] Appl. No. 819,746

[22] Filed Apr. 28, 1969 [45] Patented June 15, 1971 [73] Assignee Ateliers Et Chantiers Du llavre Duchesne & Bassiere Et Augustin Normand Reunis Le Havre Selne-Martime, France [32] Priority Oct. 21, 1968 33] France [54] DEVICE FOR STABILIZING THE TRIM OF A FLOATING OBJECT 5 Claims, 2 Drawing Figs.

[52] 0.8. CI 114/125 [51] Int. Cl. 1363b 43/06 [50] Field of Search 114/125, 124, 16.3, 16

[56] References Cited UNITED STATES PATENTS 732,920 7/1903 Cable 114/125 3,397,664 8/1968 Slager et a1. 114/124 Primary Examiner-Trygve M. Blix Attorney-lrving M Weiner ABSTRACT: The device for stabilizing the trim of a floating object comprises a mass of liquid contained in an enclosure inside of which is guided a piston associated with a jack, an installation comprising a variable delivery pump and a forcing pump for supplying a hydraulic motor whose output shaft is coupled up beyond an inertia flywheel to the driving shaft of a variable delivery pump supplying said jack, the pump being servo-controlled by the disturbing torque undergone by the floating object.

PATENTE D JUN 1 51971 3 584,591 SHEET 1 BF 2 PATENTEDJUNISIHYI 3584.591

SHEET 2 [IF 2 DEVICE FOR STABILIZING THE TRIM OF A FLOATING OBJECT The present invention relates to a trim stabilizer that can be incorporated or added to any floating object for neutralizing in a general manner, partially or completely, angular disturbing movements caused, for instance by swell.

The device of the invention is conceived so as advantageously to form an antirolling or antipigching stabilizer capable of adapting the righting torque to the best advantage that it supplies as a function of the pertubating torque undergone.

According to the invention, the stabilizing device comprises a transfer assembly of a liquid mass comprising, inside a chamber or enclosure containing said mass, at least one division part guided in displacement and associated with at least one jack able to be supplied by at least one installation comprising a driving motor of a variable delivery pump and a force pump for feeding a hydraulic motor whose output shaft is coupled to at least one motor flywheel to the driving shaft of a variable delivery pump supplying the jack, and whose servodrive is controlled by a servo and detection chain of the disturbing torque undergone by the floating object.

Various other characteristics of the invention will be revealed by the detailed description which follows.

An embodiment of the invention is shown, by way of nonrestrictive example in the accompanying drawings.

FIG. 1 is a diagram showing the various constitutive members of the trim stabilizing device.

FIG. 2 is a partial diagrammatic perspective view showing, on a larger scale, the particular embodiment ofone ofthe constitutive members of the stabilizing device.

According to the invention, the device comprises a transfer assembly 1 shown in FIG. 2 in its application to antirolling stabilization of a ship whose hull is diagrammatized at 2. According to this embodiment, the transfer assembly 1 is placed inside a transfer chamber 3 transversal to the longitudinal axis of the hull 2 to provide communication for the lower parts of two lateralenclosures 4 extending vertically. The chamber 3 contains a liquid mass 5 also rising in the inoperative state partly inside lateral enclosures 4.

The transfer assembly 1 essentially comprises a movable member or piston or division part 6 whose section is complementary to that of the chamber 3 inside which said piston is vertically maintained by horizontal guide ways 7. Although not shown, it will be apparent that the piston or division part 6 could be placed horizontally on the ships side, for instance. Each runway 7 can be made in several manners, particularly by a guide rod 8, of cylindrical section, for instance, made integral with the piston or division part 6 for sliding in one or more bearings 9. The guiderods 8 can be provided in pairs on either side of the piston or division part 6. The latter is also connected to the ends of piston rods 10 and 11 of two singleacting opposed hydraulic jacks 12 and 13 whose cylinders 14 and 15 are articulately mounted on supports 16 and 17. In certain cases the jacks 12 and 13 can be replaced by a single double-acting and double-rod jack.

The jacks l2 and 13 are intended to be alternately supplied with hydraulic pressure fluid, so as to drive the piston or division part 6 in one direction or the other inside the chamber 3 so as to displace the center of gravity of the liquid mass 5 and create a kind of straightening antagonist torque to the disturbing torque undergone by the ship.

According to the'size of the ship, the power required for displacing the piston or division part 6 varies considerably and can even reach to very great values relatively to the mean power consumed. Also, it should be noted that it is advisable to supply a certain power to the jacks for displacing the piston or division part 6 but that in othercases the jacks must also be capable of receiving and absorbing a certain energy transmitted by the liquid mass 5 exerting a thrust on the piston or division part 6.

To comply with these characteristics, the invention provides for ensuring the hydraulic pressure fluid of the jacks 12 and 13 by means of a feeding installation 18 shown in FIG. 1. According to said figure, the installation 18 comprises a driving motor 19 for a variable delivery hydraulic pump 20 self-regulated for pressure whose intake is branched to a tank or cistern 21. The discharge of the variable delivery pump 20 is connected on to the input of a hydraulic motor 22 whose output shaft 23 is coupled up to the driving shaft 26 of an inertia flywheel 25, The shaft 26 is itself coupled up to the driving shaft 28 of a variable delivery pump 29 provided for supplying in closed circuit the jacks 12 and 13 by means of a servocontrol.

The motor 19 is also provided for ensuring the drive of a supplemental force pump 30 whose intake is connected to a tank of cistern 3] that can obviously be the same as that supplying the variable delivery pump 20. The outlet or discharge of the pump 30 is connected to the outlet of the variable delivery pump 20 and comprises, above this connection, a normally closed pressure responsive antireturn or retaining valve 32. A normally open safety valve 35 enables the pump 30 to be made inoperative for speeds less than or equal to the nominal speed of the inertia flywheel 25. The outlet or discharge of the hydraulic motor 22 comprises above the return to the cistern, a delivery pressure regulator 33 as well as a calibrated flow restricting opening 34 provided in derivation and intended to establish, on the one hand, a counterpressure near to a predetermined force pressure for the nominal speed of the inertia flywheel 25, and on the other hand, a counterpressure varying with the square of the rotation speed of said flywheel for speed values exceeding the nominal speed of the flywheel.

in starting up the supply installation described above, the rotation of the motor 19 causes the variable delivery pump 20 to turn, whose oil delivery drives the hydraulic motor 22. The constant torque drive of the motor 22 ensures, the putting into rotation of the inertia flywheel 25 which progressively reaches its nominal speed in driving the pump 29 whose delivery during this phase is regulated at zero. The stabilizing device is then ready to function.

In the case of an urgent necessity for considerable power, for example, for supplying the jack 13 when the piston or partition part 6 is required to slide in the direction of the arrow f in order to displace the liquid mass 5 in the corresponding direction with a view to setting up a counter action corrector torque to a disturbing torque undergone by the ship, the pump 29, whose servo drive is controlled for supplying said jack 13 and providing it with a power in relation with the correcting torque to set up, is driven by the inertia flywheel 25 so that the driving motor 19 of the variable delivery pump 20 is not required to provide a power exceeding its nominal power, When the power to be provided diminishes and tends to be cancelled out, the inertia flywheel 25 is no longer required to provide supplementary power and tends, therefore, progressively to pick up its nominal speed so that the supply installation 18 is once more in its initial working conditions.

ln the case when the balance of power exchanged between the supply installation 18 and the transfer assembly 1 is balanced by a force received, for instance when the liquid mass 5 momentarily subjected to a disturbing torque applied to the ship tends to cause the displacement in one direction or the other of the piston or partition part 6, the pump 29 then tends to behave as a motor and drives the flywheel 25 at a speed exceeding its nominal speeds. In the case of mean excess speed of the inertia flywheel 25, the valve 32 opens so that the supplementary delivery of the forcing pump 30 is supplied to the hydraulic motor 22 also driven at excess speed by the action of the inertia flywheel 25, It should be noticed that flywheel 25 cannot, in any case, be driven at excess speed beyond a predetermined value, owing to the presence of the regulator 33, and calibrated opening 34 intended to set up a safety counterpressure braking the rotation of the motor 22 for rotation speeds in the vicinity of, or exceeding, the nominal speed of the inertia flywheel 25, One is thus assured,

in all cases, of limiting excess speed of the motor 22, the inertia flywheel 25 and the pump 29 while having the necessary reserve of power distinctly exceeding the nominal power of the driving motor 19. In other words, the installation allows a driving motor 19 to be available of a power less than the peak power likely to be required by said installation, this excess power being supplied by the kinetic energy stored up by the inertia flywheel and restored by means of variation of the reasonable rotation speed of said flywheel.

It is obvious that the installation 18 can comprise several inertia flywheels and operate the sliding of one or more pistons or partition parts 6, or, eventually, be associated with other similar installations for controlling the displacement of a single piston or partition part.

The servocontrol of the distribution slide-valve for the pump 29 is controlled by a servo chain able to estimate the value of the disturbing torque applied to the ship, so as to control the value of the compensating antagonizing torque. This servo chain can comprise a detector of the angle of the trim change of the ship, a detector of the angular speed of this change of trim and a detector of the second derivative of the angle of the trim change eventually associated with a corrector system which is a function of these latter, as well as a servomotor controlling, by servo rods, the servocontrol of the variable delivery pump 29.

The invention is not restricted to the embodiment shown and described in detail, for various modifications can be applied to it without going outside its scope. In particular, it is possible to effect the supplying of the jacks l2 and 13 opposite the piston rods, obviously taking into account the inverting of the supply for a displacement in the same direction.

I claim:

1. Apparatus for stabilizing the trim of a floating object comprising a chamber to contain a mass of liquid displaceable to counter a torque against a floating object,

a movable member within said chamber to displace the liquid,

a hydraulic power element including a piston operatively connected to said movable member,

a flrst variable delivery pump having an outlet in communication with said hydraulic power element,

a hydraulic motor,

a second variable delivery pump in communication with and driving said hydraulic motor, said second variable speed pump driven at a nominal speed,

an inertia flywheel operatively connectingsaid hydraulic motor to said first variable delivery pump to drive said first variable delivery pump at a speed in excess of the nominal driven speed of said second variable delivery pump.

2. Apparatus for stabilizing the trim of a floating object as defined by claim 1, the addition of a supplemental driven pump having an outlet in communication with said second variable delivery pump, and a normally closed valve responsive to a predetermined excess in the speed of said inertia flywheel to render said supplemental driven pump effective.

3. Apparatus as defined by claim 2, wherein said second variable delivery pump and said supplemental pump are driven by a motor, and a control member responsive to a decrease in the speed of said flywheel below a predetermined nominal speed to render said supplemental pump effective.

4. Apparatus as defined by claim 3 wherein said control member is a pressure responsive valve in communication with the hydraulic pressure at said hydraulic motor.

5. Apparatus as defined by claim 4 with the addition of a pressure regulator in communication with hydraulic motor, and a flow restriction in parallel with said regulator and in communication with said hydraulic motor. 

1. Apparatus for stabilizing the trim of a floating object comprising a chamber to contain a mass of liquid displaceable to counter a torque against a floating object, a movable member within said chamber to displace the liquid, a hydraulic power element including a piston operatively connected to said movable member, a first variable delivery pump having an outlet in communication with said hydraulic power element, a hydraulic motor, a second variable delivery pump in communication with and driving said hydraulic motor, said second variable speed pump driven at a nominal speed, an inertia flywheel operatively connecting said hydraulic motor to said first variable delivery pump to drive said first variable delivery pump at a speed in excess of the nominal driven speed of saiD second variable delivery pump.
 2. Apparatus for stabilizing the trim of a floating object as defined by claim 1, the addition of a supplemental driven pump having an outlet in communication with said second variable delivery pump, and a normally closed valve responsive to a predetermined excess in the speed of said inertia flywheel to render said supplemental driven pump effective.
 3. Apparatus as defined by claim 2, wherein said second variable delivery pump and said supplemental pump are driven by a motor, and a control member responsive to a decrease in the speed of said flywheel below a predetermined nominal speed to render said supplemental pump effective.
 4. Apparatus as defined by claim 3 wherein said control member is a pressure responsive valve in communication with the hydraulic pressure at said hydraulic motor.
 5. Apparatus as defined by claim 4 with the addition of a pressure regulator in communication with hydraulic motor, and a flow restriction in parallel with said regulator and in communication with said hydraulic motor. 